The mad bomber who targeted Bar Pitti on Sixth Avenue near Bleecker Street last Friday emerged from a subway grate, tossed a smoking road flare at the eatery’s outdoor area and then made a clean getaway back underground.

Cops are reading the dozens of comments on Yelp — and other online review sites — to see if there is a link between the attack and any of the nastiest postings.

They are also talking to homeless people who roam the subway tunnels along with MTA workers as they seek potential witnesses.

“Checking lots of video and interviewing all MTA workers, mostly track workers, to see if they ever saw this guy,” said a source.

While the police have not identified any of the suspect postings, a scan of the Bar Pitti Yelp page — where the restaurant got 3.5 out of 5 stars — showed plenty of griping about service.

Bar Pitti, 268 Sixth Ave.The entire sidewalk cafe outside this 16-year-old Village stalwart is one of the most popular hot spots south of 14th Street.Diaene Cohe

“Four of us spent $309 to have the menus snatched away from us after ordering, our wine glasses overfilled as in ‘drink up and get out,’ and such nasty attitude I kept waiting for the candid cameras to pop out,” one reviewer wrote.

Another fumed: “They were hostile, aggressive, rude and pretentious,” calling it “the worst service you will ever experience.”

On Monday, the police released a second video of the suspect crawling out of a subway access grate and hurling the smoke bomb.

Celebrity diners at Bar Pitti — such as actress Rose McGowan — breathed in the smoke, but no one was injured.